fix backtrace printed when cannot get lock.
change lock error handling code so exceptions have useful info and
exception handling in one place.
add test case for when cannot get lock.
#!/bin/sh
cat <<'EOF' > merge
#!/bin/sh
echo merging for `basename $1`
EOF
chmod +x merge
mkdir t
cd t
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "1000000 0"
hg update 0
echo This is file c1 > c
hg add c
hg commit -m "commit #2" -d "1000000 0"
echo This is file b1 > b
echo %% no merges expected
env HGMERGE=../merge hg update -m 1
cd ..; /bin/rm -rf t
mkdir t
cd t
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "1000000 0"
hg update 0
echo This is file c1 > c
hg add c
hg commit -m "commit #2" -d "1000000 0"
echo This is file b2 > b
echo %% merge should fail
env HGMERGE=../merge hg update -m 1
echo %% merge of b expected
env HGMERGE=../merge hg update -f -m 1
cd ..; /bin/rm -rf t
echo %%
mkdir t
cd t
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "1000000 0"
echo This is file b22 > b
hg commit -m "commit #2" -d "1000000 0"
hg update 1
echo This is file c1 > c
hg add c
hg commit -m "commit #3" -d "1000000 0"
echo 'Contents of b should be "this is file b1"'
cat b
echo This is file b22 > b
echo %% merge fails
env HGMERGE=../merge hg update -m 2
echo %% merge expected!
env HGMERGE=../merge hg update -f -m 2
cd ..; /bin/rm -rf t
mkdir t
cd t
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "1000000 0"
echo This is file b22 > b
hg commit -m "commit #2" -d "1000000 0"
hg update 1
echo This is file c1 > c
hg add c
hg commit -m "commit #3" -d "1000000 0"
echo This is file b33 > b
echo %% merge of b should fail
env HGMERGE=../merge hg update -m 2
echo %% merge of b expected
env HGMERGE=../merge hg update -f -m 2
cd ..; /bin/rm -rf t